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Biomedical subjects

O Iimura

Publications and source records attributed to O Iimura.

At least 109 records · Page 6Linked to original sources
PubMed1988

Dose-effect relationship of carvedilol in essential hypertension. An open study.

This study was performed to find the optimal dose of carvedilol, in terms of efficacy and safety, in Japanese patients with mild to moderate essential hypertension. 134 patients with blood pressure greater than 160/95 mm Hg after a 4-week placebo run-in period were initially given carvedilol 5mg once daily. The dose was increased to 10 and 20mg at 4-weekly intervals if the target blood pressure was not achieved. The duration of treatment was 12 weeks. After 12 weeks' administration, the average blood pressure was significantly (p less than 0.001) reduced from 170/101 to 150/91 mm Hg. The hypotensive activity of carvedilol 5mg was mild, but sufficient hypotensive effect was observed in 65% of patients receiving up to 20 mg/day. No significant postural changes in blood pressure were observed. Although heart rate was significantly decreased (77 to 66 beats/min, p less than 0.001), no patient was judged to have bradycardia. Side effects occurred in 5.2% of patients. Carvedilol 10 to 20mg once daily is considered to be an effective and safe treatment for essential hypertension.

Adrenergic beta-Antagonists↗
PubMed1988

Urapidil in patients with severe hypertension and in long-term treatment.

In order to evaluate the usefulness of urapidil in the treatment of severe hypertension and in the long-term treatment of essential hypertension, two open multicentre studies were performed. In one study, 34 outpatients with diastolic blood pressure exceeding 105 mmHg following treatment with a combination of a diuretic and a sympatholytic or a diuretic and a beta-blocker were additionally given 15-60 mg urapidil twice a day for 8 weeks or more. The responder rate was 73.5%. The pulse rate did not change throughout. Side effects such as dizziness and malaise were observed in five patients (14.7%), but they were slight and did not require withdrawal of treatment. The other study included 95 outpatients with essential hypertension (World Health Organization stages I or II), 15-60 mg urapidil twice a day for 1 year or more in monotherapy (n = 48) or in combined therapy with a thiazide (n = 47). Under both therapies, diastolic blood pressure was reduced significantly at week 4, further reduced at week 12 and remained stable until week 52. Responder rates were 82.9% in monotherapy and 78.4% in combined therapy. Two patients (4.2%) taking monotherapy and six patients (12.8%) taking combined therapy were withdrawn due to inadequate blood pressure control or to side effects. These results indicate that urapidil is useful in severe and in long-term hypertension.

Adrenergic beta-Antagonists↗
PubMed1988

Siblings with left ventricular diverticulum and hypertrophic cardiomyopathy.

This report describes very rare siblings who had a left ventricular muscular diverticulum and hypertrophic cardiomyopathy. The first case is a 16-year-old male. On two-dimensional echocardiography, a left ventricular muscular diverticulum in the posterior wall and mitral valve prolapse were detected. The former was verified by left ventriculography. Endomyocardial biopsy showed findings compatible with hypertrophic cardiomyopathy. The second case is a 13-year-old female. Two-dimensional echocardiography revealed a left ventricular muscular diverticulum in the same location as that of the first case, and mitral valve prolapse as well. The former was confirmed by left ventriculography. The endomyocardial biopsy findings were compatible with hypertrophic cardiomyopathy. The coronary angiograms were normal in both cases. To our knowledge, familial appearance of a left ventricular diverticulum has not yet been reported, and a left ventricular diverticulum at the posterior wall in cases with hypertrophic cardiomyopathy is very rare.

Adolescent↗
PubMed1987

Effect of ramipril, a new angiotensin converting enzyme inhibitor, on diurnal variations of blood pressure in essential hypertension.

The effect of ramipril on diurnal variations of blood pressure was studied in patients with mild to moderate essential hypertension in groups given once- (n = 18) and twice-daily (n = 21) administration with daily dosages ranging from 2.5 to 10 mg. After ramipril treatment, the blood pressure of patients in both groups was significantly reduced, and no significant differences in diurnal variation of blood pressure were observed between the 2 groups. The pulse rate did not change after administration of ramipril and no serious side effects were observed. In consideration of patient compliance, once-daily administration of ramipril seems to be optimal for the treatment of essential hypertension.

Adult↗
PubMed1987

Efficacy and safety of ramipril (HOE 498) in the treatment of hypertension: dose finding study.

An open-label, prospective multicenter trial of ramipril was performed. The agent was administered once daily at an initial dosage of 1.25 mg and this was increased, when necessary, up to 10 mg with intervals of 2 weeks for 8 weeks. Effectiveness in 46 patients with mild to moderate essential hypertension was 28.1% at a dosage of 1.25 mg, 52.2% at 2.5 mg, 69.6% at 5 mg and 78.3% at 10 mg of ramipril alone. In 27 patients receiving baseline therapy with a thiazide diuretic, a subsequent administration of ramipril showed effectiveness in 11.1% for 1.25 mg, 48.1% for 2.5 mg and 70.4% for 5 mg. Adverse effects occurred in 11.7% of patients overall and were not serious. One patient was withdrawn because of severe headache; the other patients tolerated the treatment well. A dosage of 2.5 to 10 mg of ramipril will probably be appropriate for further evaluation of the effectiveness of this agent in a double-blind study.

Adult↗
PubMed1987

The pathophysiological role of renal dopamine, kallikrein kinin and prostaglandin systems in essential hypertension.

In order to clarify the relationship and the pathophysiological role of renal dopamine, kallikrein-kinin and prostaglandin systems in essential hypertensives, the effects of dopamine on these systems and renal sodium handling were investigated. Basal levels of kallikrein, kinin and prostaglandin E2 in essential hypertensives were significantly lower than those in normotensives. Those of kallikrein and kinin were obviously more suppressed in the low renin group than in the normal renin group, but no significant difference in prostaglandin E2 was found in either subgroup. Urinary dopamine excretion was significantly lower in the low renin essential hypertensives, while no significant difference was found between normotensives and normal renin essential hypertensives. Kallikrein activity and prostaglandin E2 were significantly increased in essential hypertensives by dopamine infusion, and no significant difference was found in kallikrein-quantity and kinin between normotensives and essential hypertensives after the infusion. These increases of kallikrein and kinin were significantly higher in the low renin group than in normal renin group, but those of prostaglandin E2 were not. Urine volume, urinary sodium excretion and fractional excretions of sodium and inorganic phosphorus were all increased in both normotensives and essential hypertensives after dopamine infusion. The increases of these were significantly greater in essential hypertensives than in normotensives, and greater in the low renin group than the normal renin group. From these results, it was suggested that the dopamine, kallikrein-kinin and prostaglandin E2 system have a close relationship with each other, and the suppression of these systems may contribute to the pathophysiology of essential hypertension, especially in the low renin group.

Dinoprostone↗
PubMed1987

Plasma levels of human atrial natriuretic peptide in patients with hypertensive diseases.

Three types of antihuman atrial natriuretic peptide antiserum were obtained. From the study of cross-reactivity to human atrial natriuretic peptide fragments, it was suggested that antisera-1, -2, and -3 are mostly specific to 1-28, 5-25, and the ring structure, respectively. The estimated values of this hormone were significantly lower in the order of antisera-1, -2, and -3. Moreover, high performance liquid chromatographic study showed that various types of fragments of atrial natriuretic peptide exist in human plasma. These findings suggested that the highly specific antiserum to 1-28 human atrial natriuretic peptide such as antiserum-1 should be used to estimate the 1-28 human atrial natriuretic peptide levels in human plasma. From the study by using antiserum-1, it was concluded that the plasma human atrial natriuretic peptide increased in essential hypertensives, and in patients with primary aldosteronism, chronic renal failure, and malignant hypertension. Regarding the pathophysiological significance of increased plasma atrial natriuretic peptide, it is unlikely that this plays an important role in the etiology of essential hypertension or other hypertensive diseases, because the plasma level of this hormone is elevated in these patients. The increase of plasma atrial natriuretic peptide level in these patients should be considered to be a secondary or compensatory reaction to high blood pressure.

Aldosterone↗
PubMed1987

The pathophysiological role of renal dopaminergic activity in patients with essential hypertension.

To evaluate the role of the renal dopaminergic system on renal water-sodium metabolism patients with essential hypertension (EHT), urinary excretion of dopamine, urinary excretion of sodium (UNaV) and fractional excretion of sodium (FENa) were all investigated before and after the administration of dopamine (3 micrograms/kg/min, intravenous infusion for 60 minutes), dopamine antagonist, metoclopramide (8 mg/m2 BSA, intravenous injection) or mild sodium loading in both normotensive subjects and benign EHT. In the basal values, no significant difference in urinary excretion of free (u-fDA), conjugated (u-cDA) or total dopamine (u-tDA) was found between normotensives and hypertensives. However, low renin EHT showed a pronounced reduction in u-fDA compared with normotensis subject and (NT) normal renin EHT. In this study, a significant reduction of u-cDA and of u-tDA was also found in those patients with low renin essential hypertension. In the normotensive and essential hypertensive groups UNaV or FENa showed a positive correlation with u-fDA (measured simultaneously), but not with u-tDA or u-cDA. The regression line between u-fDA and UNaV or FENa in EHT was shifted towards a lower u-fDA level than in NT. UNaV and FENa were increased by dopamine infusion and were decreased by metoclopramide injection in both NT and EHT. Changes of UNaV and FENa following dopamine or metoclopramide, showed a negative correlation with u-fDA measured immediately before the administration of these drugs. The enhanced natriuretic response to infused dopamine and the attenuated antinatriuretic response to injected metoclopramide were significant in low renin EHT, when compared with NT or normal renin EHT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Study on the atherosclerosis mechanism in chronic hemodialysis.

In order to clarify whether hemodialysis treatment accelerates atherosclerosis, forty-two patients undergoing chronic hemodialysis were investigated. Because it is non-invasive and repeatable, aortic calcification on chest-XP was used as an index of atherosclerosis. No patients had evidence of calcified atherosclerosis at the start of hemodialysis therapy. The patients were divided into three groups according to vascular changes. Group 1 (20 patients) showed no calcification during the observation period. Group 2 (11 patients) had mild or moderate aortic calcification (thin linear aortic calcification). In group 3 (11 patients), massive and severe calcification was accelerated by hemodialysis. 18 parameters which might be considered to promote atherosclerosis were evaluated in each group. The age in group 3 was 53.8 +/- 10.4 (mean +/- standard deviation) years, which was older than the 42.1 +/- 12.6 year age in group 1 (p less than 0.025). Duration of dialysis in group 3 was 121.9 +/- 30.5 months, which was significantly longer than the 82.0 +/- 31.0 months in group 2 (p less than 0.01) and the 77.3 +/- 55.3 months in group 1 (p less than 0.025). Serum HDL-cholesterol levels in groups 2 (23.0 +/- 4.5 mg/dl) and 3 (20.9 +/- 6.6 mg/dl) were significantly lower than the 28.6 +/- 8.3 mg/dl in group 1, (p less than 0.025 and p less than 0.05, respectively). Serum parathormone-C level in group 3 was 14.7 +/- 8.6 ng/ml, which was significantly higher than the 6.1 +/- 6.0 ng/ml level in group 1 (p less than 0.01) and the 5.0 +/- 7.8 ng/ml level in group 2 (p less than 0.025). In discriminant analysis, age, duration of dialysis, hematocrit, serum HDL-cholesterol, parathormone-C, and alkaline phosphatase level were the independent factors used to distinguish the three groups. These findings suggest that 1) aging is a basal factor in the promotion of atherosclerosis, 2) hypo-HDL cholesterolemia is a major factor in the early phase of atherosclerosis, 3) hyperparathyroidism could have an important role in the late phase of atherosclerosis, 4) dialysis itself might promote atherosclerosis directly, and 5) blood pressure level is not major factor for atherosclerosis over a long observation period, at least in our study.

Adult↗
PubMed1987

Kallikrein in the male reproductive system.

Male genital organs were stained by the peroxidase-antiperoxidase (PAP) method to know the location of kallikrein. Sertoli cells of the testis, epithelial cells that existed from the body to the tail of the epididymis, and glandular cells of the prostate were specifically stained showing that kallikrein was produced in these cells. The concentration of kallikrein in the semen specimens mainly from patients with male sterility and from those who were subjected to vasoligation and in the prostatic fluid specimens from normal controls were measured by radioimmunoassay (RIA). The results of column chromatography suggested that kallikrein combined with the other substances to form a high molecular compound in the semen. The kallikrein level in the semen from the normal control was 40.4 +/- 21.3 ng/ml, which was more than 10 times that in the blood. The value tended to increase with the decrease of the number of spermatozoa. The kallikrein level in the semen from patients with azoospermia was 74.2 +/- 23.5 ng/ml, which was significantly higher than that of the normal control. There was no significant correlation between the kallikrein level and the sperm motility. The kallikrein level in the semen from the patients subjected to vasoligation, which did not contain the semen originated from the testis, and that in the prostatic fluid from the normal control were 20-28 ng/ml. That amount was considered to be secreted from the prostate. The oral administration of hog kallikrein tablet augmented seminal human kallikrein and Acid-P secretion. Moreover, an improvement of seminalysis was observed following long term administration of 600 U/day of hog kallikrein in the male infertile patients. This drug might be useful to treat the male infertile patients with this disorder.

Adult↗
PubMed1987

The effect of low dose carvedilol on circadian variation of blood pressure in patients with essential hypertension.

The effect of once daily low-dose carvedilol on circadian variations of blood pressure (BP) was studied in Japanese patients with mild or moderate essential hypertension. Thirty-one patients were admitted to hospital whose BP was 150/90 mm Hg/day or greater and they participated in the study. After a placebo period of 1 week, 5 or 10 mg carvedilol was given once daily in the morning for 3 to 7 days, and if BP reduction was not sufficient, the dose was increased to 20 mg daily. The blood pressure variation was monitored before and 1, 2, 4, 6, 8, 10, 12, and 24 h after administration of the drug on the last day of placebo and final dose of carvedilol. Of the 31 cases receiving carvedilol once daily, cumulative effectiveness (13 mm Hg reduction in mean BP) was 48.4% at 10 mg/day and 54.8% at 20 mg/day. Both systolic and diastolic pressures decreased significantly and heart rate decreased slightly. There was no significant difference between the standard deviations of BP on the last days of the control period and the carvedilol treatment. The difference between maximum and minimum BP during the day was not significant between the two periods. Circadian variations of heart rate were also not significantly different for the two periods. This indicates that carvedilol did not have any effect on circadian variations of BP and heart rate. The present study also suggests that low-dose carvedilol once daily may be effective in the treatment of hypertension.

Adrenergic beta-Antagonists↗
PubMed1987

Interrelation between plasma kinin and the sympathetic nervous system in normal subjects.

To investigate the relationship between plasma kinin and the sympathetic nervous system, we measured plasma kinin, norepinephrine, and angiotensin-I-converting enzyme (ACE:kininase II) activity in normal subjects. In six normal subjects, subpressor and pressor doses of norepinephrine (10 ng/kg/min and 50 ng/kg/min, respectively) were infused for 1 hour. In five normal subjects, 60-degree head-up tilting was performed for 20 minutes. After norepinephrine infusion, plasma kinin levels were decreased significantly (p less than 0.01) with the subpressor dose of norepinephrine and were further decreased (p less than 0.01) with the pressor dose. Plasma ACE activity, however, showed no significant changes following these infusions. During the tilting, plasma kinin levels decreased significantly (p less than 0.01), whereas plasma norepinephrine levels increased significantly (p less than 0.01). From these results, the assumption of elevated levels in plasma endogenous or exogenous norepinephrine leads to a decrease in plasma kinin levels; this suggests that these two systems may be closely interrelated.

Adult↗
PubMed1987

[The systolic slipping mechanism of the anterior mitral leaflet in patients with the straight back syndrome].

The systolic slipping mechanism of the anterior mitral leaflet in patients with the straight back syndrome (SBS) was evaluated by two-dimensional echocardiography in 16 SBS patients and 11 normal subjects. Doppler echocardiography was performed in all subjects to detect mitral regurgitation. The site of the mitral slipping was identified in a centromedial region of the anterior mitral leaflet in these patients. The ellipsoidal index (long axis/short axis) of the left ventricle was greater in SBS patients than in normal subjects. The left ventricular wall had a characteristic motion in SBS. The lateral wall contracted well, while the posterior septum and inferoposterior wall were hypokinetic. Moreover, the anterolateral papillary muscle moved horizontally during systole, while the posteromedial papillary muscle moved anteriorly. There was a significant correlation between the distance of slipping of the anterior mitral leaflet and the PL/PM ratio (r = -0.39, p less than 0.001), where PL is the distance from the gravity point of the left ventricle to the midpoint of the anterolateral papillary muscle, and PM is that from the gravity point of the left ventricle to the posteromedial papillary muscle. Mild mitral regurgitation was identified in four cases with SBS by Doppler echocardiography, and this regurgitant jet was directed from the posterior mitral leaflet to the posterior wall of the left atrium. These results suggest that the systolic slipping of the anterior mitral leaflet in SBS might be caused by asynchronous papillary muscle motion. This might be based on the ellipsoidal left ventricle due to the short internal dimension of the thorax.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

The pathophysiological role of water-sodium balance and renal dopaminergic activity in overweight patients with essential hypertension.

Studies were conducted to evaluate the role of water-sodium balance and renal dopaminergic activity in the hypertensive mechanisms of overweight patients with essential hypertension (EHT). The body mass index (BMI) was correlated positively with arterial pressure, plasma volume, extracellular fluid volume, or total exchangeable sodium and negatively with plasma noradrenaline concentration or plasma renin activity in patients with EHT. Fractional excretion of sodium (FENa) was significantly lower in overweight patients with EHT than that in normal-weight patients with EHT. Hypotensive effects of sodium restriction or the natriuretic response to infused dopamine was more remarkable in overweight than in normal-weight patients with EHT. Urinary excretion of free dopamine (UDA) was correlated positively with simultaneously measured urinary excretion of sodium or FENa and negatively with the natriuretic response to dopamine infusion. In addition, UDA was positively correlated with the BMI in normal-weight patients with EHT, whereas the relation between UDA and BMI was significantly negative in overweight patients with EHT. These findings suggest that the expansion of body fluid volume and sodium might result from the blunted natriuretic ability due to an attenuation of the renal dopaminergic activity in overweight patients with EHT. The expansion of body fluid volume and sodium may play an important role in the hypertensive mechanisms of overweight patients with EHT.

Adult↗
PubMed1986

Interrelation between the renin-angiotensin system and kallikrein-kinin system in patients with essential hypertension.

In order to investigate the relationship between the kallikrein-kinin (K-K) system and renin-angiotensin (R-A) system, plasma kinin (pKIN), plasma angiotensin II (pAII), plasma renin activity (PRA) and angiotensin converting enzyme activity (ACEA) were determined in 19 essential hypertensives (EHT). pKIN and pATII measurements were performed by highly sensitive radioimmunoassay (RIA), both of which were established in our laboratory. The assay sensitivity of pKIN and pAII were 0.5 pg/tube and 0.1 pg/tube, respectively. In pKIN RIA, pKIN was extracted by ethanol from 0.8 ml of plasma obtained with a syringe containing kinin generating and destroying enzyme inhibitors. In pAII RIA, pAII was measured directly in small amounts of 50-100 microliter, unextracted plasma samples. The level in pAII was significantly higher (p less than 0.05) in the normal renin group (NRH: n = 13) as compared with low renin group of EHT (LRH: n = 6). However, no significant difference was found in pKIN and ACEA between these two groups. Although a significantly positive correlation was observed between pAII and PRA (p less than 0.001) in EHT, the ratio of pAII/PRA tended to be higher in LHR than in NRH. ACEA correlated positively with pAII (p less than 0.01) or PRA (p less than 0.02), respectively. On the other hand, a significant negative correlation was also found between pKIN and pAII (p less than 0.05). From these findings, it was assumed that there was a closed relationship between R-A and K-K systems, and that angiotensin converting enzyme (kininase II) might play some role in the interrelation between both systems.

Adult↗